Supervisory system



1944- c. E. STEWART 2,360,172

SUPERVISORY SYSTEM Filed Feb. 11, 1943 Inventor: C gde E. Stewart,

by W J w His Attornegf Patented Oct. 10, 1944 SUPERVISORY SYSTEM ClydeE. Stewart, Upper barby, Pa., assignor to General Electric Company, acorporation of New York Application February 11, 1943, Serial No.475,491

Claims.

My invention relates to supervisory systems and particularly to suchsystems in whichany one of a plurality of apparatus units at a remotestation can be selected and individually operated from a dispatchersoffice in response to the transmission of current impulses over asuitable channel of communication interconnecting the remote station andthe dispatchers office. In such a system, it has been the practiceheretofore to provide at the dispatchers oflice for each controllableapparatus unit at the remote station a group of lamps which areselectively operated so as to indicate the position of the correspondingapparatus unit and, also, the completion of certain operations of thesupervisory equipment while it is functioning to select and place thecorresponding apparatus unit under the control of the dispatcher.Heretofore, each group of relays has usually consisted of four lamps andhas had associated therewith an individual two-position disagreement keyand an individual twoposition select key. Each group of four lamps hasincluded a red lamp which was lighted when the corresponding apparatusunit was in a predetermined position, such as the closed positionthereof; a green lamp which was lighted when the corresponding apparatusunit was in a different predetermined position, such as the openposition thereof; a white lamp which was lighted when the position oftheassociated disagreement key, the positions of which correspond to thepositions of the associated apparatus unit, did not agree with theposition of the associated apparatus unit; and an amber lamp which waslighted when the corresponding apparatus unit Was properly selected bythe supervisory equipment for control by the dispatcher. Each select keywas arranged so that'when it was moved to one of its two positions, theoperation of the supervisory equipment was initiated to cause it toselect the apparatus unit corresponding to the operated select key formanual control by the dispatcher, and when the select key was moved backto its normal position, the supervisory equipment was restored to itsnormal position.

One object of my invention is to provide in a supervisory system of theabove-mentioned type an arrangement of devices and circuits whereby thenumber of lamps and keys at the dispatchers office individual to eachvapparatus unit at the remote station is reduced to a minimum withouteliminating any of the indicating features of the prior 'artarrangements. 7

In accordance with my invention; I provide,

in the particular embodiment of my invention shown in the accompanyingdrawing, an arrangement whereby only two lamps and a singlethree-position control key are required at the dispatchers oflice foreach apparatus unit at the remote station.

My invention will be better understood from the following descriptionwhen taken in connection with the accompanying drawing, the single myinvention embodied in an automatic supervisory system of the codeselector type and particularly to the type of supervisory systemdisclosed in detail in United States Letters Patent 2,253,147, grantedAugust 19, 1941, on an application filed by me and assigned to theassignee of the present application. In order to simplify thedisclosure, only those parts of the system disclosed in detail in theaforesaid Letters Patent 2,253,147 are shown in the accompanying drawingas are deemed necessary for a clear understanding of the presentinvention when taken in connection with the following description.

Also, to facilitate a comparison with the disclosure of the aforesaidLetters Patent, the devices in the present disclosure are designated bythe same characters as the corresponding devices in the aforesaidLetters Patent to which reference may be made in case a completedetailed disclosure of the circuit connections of the various devicesconstituting the complete supervisory system is desired.

As shown in the accompanying drawing, the

supervisory system includes two conductors L1 and L2 extending between adispatchers ofiice DO and a remote station RS.

For the purpose of this description, it is assumed that, except for theconnections at the dispatchers oflice D0 of the indicating lamps andcontrol keys individual to each apparatus unit, the control devices ofthe supervisory system and connections thereof at both the dispatchersoffice DO and the remote station RS are the same as those disclosed inthe aforesaid Letters Patent 2,253,147. At the dispatchers office DO,there are two individual indicating relays, such as IGI and IRI, foreach apparatus unit, such as AUI at the remote station RS. As describedin detail in the aforesaid Letters Patent, when the supervisoryequipment is at rest, one of the relays of each groupis energizeddepending upon the position of the corresponding apparatus unit at theremote station, and the energized relay effects the lighting of anassociated indicating lamp. For example, if the apparatus unit AUl,which is shown as a circuit breaker, is closed, the correspondingindicating relay IRI is energized and completes a lighting circuit forthe associated red lamp LRI' whereas if the apparatus unit A'U'! isopen, the corresponding indicating relay IGI is energized and completesa lighting circuit for the associated green lamp LGI. When the operationof the supervisory equipment is initiated in response .to the operationof a select key individual to an apparatus unit to effect theestablishment of a control connection to that apparatus unit, both ofthe indicating relays individual to the operated select key aredeenergized as soon as the group finder selector switch at thedispatchers office stops in the position thereof allotted to theoperated select key. These two indicating relays then remain deenergizeduntil after the select and check codes and the indication impulse havebeen transmitted. If the select and check codes agree, the receipt ofthe indication impulse which follows the check code effects theenergization of the indicating relay corresponding to the position ofthe selected apparatus unit. For example, if the apparatus unit A'Ul isthe selected apparatus unit and it is open at the time the selection isestablished, the relay IGI is energized in response to the transmissionof the indication impulse whereas if the apparatus unit AUl is closed,the indication impulse effects the energization of the indication relayIRI.

Each time the dispatcher operates a selected apparatus unit, theenergized indicating relay individual to the selected apparatus unit isdeenergized in response to the operation of the masteroperate key by thedispatcher, and both of the indicating relays corresponding to theselected apparatus unit remain deenergized until after the operatingimpulse has been terminated by the dispatcher opening the master operatekey and the supervisory equipment has operated to effect thetransmission of another indicating impulse corresponding to the positionof the operated apparatus unit. This new indicating impulse selectivelyenergizes the indicating relays individual to the operated apparatusunit in accordance with the new position thereof.

When the supervisory equipment is restored to its normal position by thedispatcher opening the operated select key, the supervisory equipment isautomatically restored to its nor mal position without deenergizing thelast indicating relay to be energized while the selection wasestablished.

When the supervisory equipment is at rest in its normal position and anapparatus unit at the remote station RS changes its position, thesupervisory equipment operates automatically to select the group ofindicating relays at the dispatchers office individual to the apparatusunit that has changed its position. After this selection has been made,the selected indicating relay which was energized at the time theapparatus unit changed its position, is deenergized and then the properone is energized to effect the lighting of the associated indicatinglamps to indicate the new position of the apparatus unit which haschanged its position. The supervisory equipment then automaticallyrestores to its normal position without effecting the deenergization ofthe energized indicating relay.

Ln the aforesaid Letters Patent 2,253,147, each group of indicatingrelays in conjunction with an associated disagreement key, associatedwith the indicating relays, controls the lighting of an associated whitelamp. Also included in each group of relays is an amber lamp which islighted when the supervisory equipment establishes a control connectionto the corresponding apparatus unit at the remote station RS.

In accordance with my present invention, I provide an arrangement forobtaining the desired indications which eliminates these white and amberlamps and one of the control keys at the dispatchers office so that onlytwo indicating lamps and a single three-position key are required foreach controllable apparatus unit at the remote station.

In order to simplify the disclosure, I have shown at the dispatchersoffice DO only one group of lamps including the red lamp LRI, the greenlamp LGI, and an associated three-position control key Kl, all of whichare individual to the apparatus unit AUl at the remote station RS. Thecontrol key Kl is a combined disagreement and select key. In oneposition of the key Ki, which corresponds to the closed position of theapparatus unit AU'l, only the contacts a of the key are closed. In asecond or mid-position of the key KI which is the position to which thekey is operated when the dispatcher desires to select the apparatus unitA'Ul for operation, all of the contacts a, b, c and d of the key areclosed. In the third position of the key Kl, which corresponds to theopen position of the apparatus unit AUl, only the contacts d of the keyare closed. The contacts a and d of the key KI correspond to thecontacts of the disagreement key DKI, and the contacts I) and 0correspond to the contacts of the select key SKI of the aforesaidLetters Patent. The contacts d of the key Kl are arranged to connect asuitable interrupting means FL in series with the lamp LGI when thecontacts I) of the relay IGI are closed, and the contacts a of the keyKl are arranged to connect the interrupting means FL in series with thelamp LRI when the contacts I) of the indicating relay IR! are closed.

The operation. of the arrangement shown in the accompanying drawing isas follows. When the supervisory equipment is in its normal at restposition and the apparatus unit AUI is in its closed position, thevarious control devices shown in the drawing are in the positions inwhich they are shown. The red lamp LRI is lighted continuously by acircuit which includes the contacts a. and the winding of the indicatingrelay IRI. The current in this circuit also maintains the indicatingrelay IRI in its energized position. The continuous lighting of the redlamp LRI, while the key Kl is in its position corresponding to theclosed position of the apparatus unit A'U'l, informs the dispatcher thatth apparatus unit A'UI is in its closed position. It will be observedthat under these assumed conditions the flashing circuit of the greenlight LGI is open at the contacts (1 of the control key Kl.

When the dispatcher desires to select the apparatus unit A'Ul foroperation, he moves the corresponding control key Kl to itsmid-position, in which position all of the contacts a, b, c and 9f thekey are closed. The closing of the contacts d of the key Kl completesthrough the contacts b of the indicating relay IGI a flashing circuitfor the lamp LGI while the associated red lamp LRI remains continuouslyenergized until the group finder selector switch of the supervisoryequipment, the operation of which is initiated by the closing of thecontacts 17 and c of the control key KI, stops in the position thereofwhich is allotted to the operated control key KI. At that time, a lowimpedance shunt circuit is completed around the winding of theindicating relay IRI by the supervisory equipment in a manner disclosedin the aforesaid Letters Patent so as to cause the relay IE! to open itscontacts a and close its contacts b. A flashing circuit is thencompleted for the red lamp LRI through the contacts I) of the indicatingrelay IRI, contacts a of the control key KI, and the interrupting meansFL. The simultaneous flashing of both of the lamps LGI and LR! informsthe dispatcher that the supervisory equipment has found thecorresponding operated control key KI and is attempting to establish aconnection to the corresponding apparatus unit A'Ul at the remotestation.

After the supervisory equipment has operated to transmit to the remotestation RS the proper select code of impulses to select the apparatusunit A'U'l and then has transmitted back to the dispat'chers oflice theproper check code of impulses followed by an indication impulsecorresponding to the position of the selected apparatus unit, which itis assumed is the closed position, the relay IR! is again energized toopen its contacts b and close its contacts a so that the red lamp LRI isagain lighted continuously whereas the green lamp LGI is lightedintermittently. The continuous lighting of one of the lamps of a groupand the flashing of the other lamp after both lamps have been flashingsimultaneously, while the associated control key is in its midposition,informs the dispatcher that the corresponding apparatus unit has beenselected by the supervisory equipment for operation by the dispatcherand that the selected apparatus unit is in the position correspondingtothe continuously lighted lamp. a

If after the apparatus unit A'Ul has been selected the dispatcherdesires to effect the opening thereof, he operates the proper masteroperate key (not shown) which eiiects, in a manner disclosed in detailin the aforesaid Letters Patent, the transmission of a control impulseover the line conductors L1, L2 which effects the opening of theapparatus unit AU'I, the deenergization of the indicating relay IRI, andthe energization of the indicating relay IGI so that the green lamp LGIis lighted continuously While the red lamp LRI is lightedintermittently.

If after the apparatus unit A'U'l has been opened the dispatcher'desiresto reclose it. he operates the proper master'operate key (not shown)which effects, in a manner described in lamp corresponding to the newposition of the apparatus unit AU'I is lighted continuously and theother indicating lamp is lighted intermittently.

When the dispatcher desires to release the selection, he moves theoperated control key KI to the position thereof corresponding to theposition then occupied by the selected apparatus unit. For example, ifthe selected apparatus unit AUl is open at the time the selection is tobe released, the dispatcher moves the control key Kl to the positionthereof in which only the contacts at are closed. The opening of thecontacts a of thecontrol key Kl interrupts the flashing circuit of thered lamp LR] so that only the continuously lighted green lamp LGIremains lighted after the control key is moved to its new position. Ifthe apparatus unit A'Ul is closed at the time the selection is released,the control key Kl is moved to its position in which only the contacts aare closed so that only the continuously lighted red lamp LRI remainslighted after the selection is released. The opening of the contacts band c of the key Kl when it is moved out of its mid-position causes, ina manner disclosed in the aforesaid Letters Patent, the supervisoryequipment to be restored to its normal position.

When thesupervisory equipment is at rest in its normal position and anapparatus unit at the remote station changes its position, thesupervisory equipment operates, in a manner disclosed in the aforesaidLetters Patent, to effect the deenergization of whichever one of thecorrespond ing indicating relays at the dispatchers office was energizedprior to the apparatus unit changing its position and then effects theenergization of the indicating relay corresponding to the new positionof the apparatus unit. For example, when the apparatus unit AU'l isautomatically opened, the supervisory equipment operates to effect thedeenergization of the indicating relay IR! and the energization of theindicating relay IGI so that the green lamp LGI is lighted continuouslyWhile the red lamp LRI is lighted intermittently. Such an operation ofthe indicating lamps, While the associated control key KI is in theposition corresponding to the closed position of the correspondingapparatus unit AU'Linforms the dispatcher that the apparatus unit AU'Ihas automatically moved to its open position. The dispatcher then movesthe control key Kl to the position thereof corresponding to the openposition of the corresponding apparatus unit so as to open the contactsa of the control key KI and thereby interrupt the flashing circuitforthe red indicating lamp LR].

While I have, in accordance with the Patent Statutes, shown anddescribed my invention as applied to a particular system and asembodying various devices diagrammatically indicated, changes andmodifications will be obvious to those skilled in the art, and Itherefore aim in the appended claims to cover all such changes andmodifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In combination, a movable apparatus unit having two positions, twoindicating relays, means for selectively controlling the operation ofsaid relays in accordance with the position of said unit, a control keyhaving a plurality of positions, a signal, means for operating saidsignal continuously in response to one of said relays being in apredetermined position and intermittently in response to said one ofsaid relays being in a different predetermined position while saidcontrol key is in a predetermined position, a second signal, and meansfor operating said second signal continuously in response to the otherof said relays being in a predetermined position and intermittently inresponse to said other of said relays being in a different predeterminedposition while said control key is in said predetermined position.

2. In combination, a movable apparatus unit having two positions, twoindicating relays, means for maintaining a predetermined one of saidrelays energized and the other relay deenergized when said unit is in apredetermined one of its positions, means for maintaining said other ofsaid relays energized and said predetermined one of said relaysdeenergized when said unit is in its other position, a control keyhaving a plurality of positions, a signal, means for operating saidsignal continuously in response to said predetermined one of said relaysbeing energized and intermittently in response to said predetermined oneof said relays being deenergized and said key being in a predeterminedposition, a second signal, and means for operating said second signalcontinuously in response to said other of said relays being energizedand intermittently in response to said other of said relays beingdeenergized and said key being in said predetermined position.

3. In a supervisory system, two stations, an apparatus unit at one ofsaid stations, two indicating relays at said other station andindividual to said unit arranged to be selectively controlled inaccordance with the position of said apparatus unit so that one of saidrelays is in a predetermined operated condition when said unit is in apredetermined position and the other relay is in a, predeterminedoperated condition when said unit is in a different predeterminedposition, a signal at said other station and corresponding to saidpredetermined position of said unit, a second signal at said otherstation and corresponding to said difierent predetermined position ofsaid unit, a control key at said other station and having two positionsrespectively corresponding to said two predetermined positions of saidunit and a third position, means for operating said first mentionedsignal continuously in response to said one of said relays being in itspredetermined operated condition and intermittently in response to saidone of said relays not being in its predetermined operated conditionwhile said control key is in its position corresponding to said firstmentioned predetermined position, means for operating said second signalcontinuously in response to said other relay being in its predeterminedoperated condition and intermittently in response to said other relaynot being in its predetermined operated condition while said control keyis in its position corresponding to said different predeterminedposition, means for operating said first mentioned signal intermittentlyin response to. said one of said relays not being in its, predeterminedoperated condition while said control key is in said third position, andmeans for operating said secparatus unit at one of said stations, twoindieating. relays at said other station and individual to said unitarranged to be selectively controlled in accordance with theestablishment of predeftermined connections while said apparatus unit isbeing started and also in accordance with the position of said apparatusunit after the selection thereof has been established so that one ofsaid relays is in a predetermined operatedcondition when said unit is ina predetermined position and the other relay is in a predeterminedoperated condition when said unit is in a different predeterminedposition, a signal at said other station and corresponding to saidpredetermined position of said unit, a second signal at said otherstation and corresponding to said different predetermined position ofsaid unit, a control key at said other station and having two positionsrespectively corresponding to said two predetermined positions of saidunit and a third position, means for operating said first mentionedsignal continuously in response to said one of said relays being in itspredetermined operated con.- dition and intermittently in response tosaid one of said relays not being in its predetermined operatedcondition While said control key is in itsposition corresponding to saidfirst mentioned predetermined position, means for operating said secondsignal continuously in response to said other relay being in itspredetermined operated condition and intermittently in response to saidother relay not being in its predetermined operated condition while saidcontrol key is in its position corresponding to said differentpredetermined position, means for operating said first mentioned signalintermittently in response to said one of said relaysnot beingv in itspredetermined operated condition while said control key is in said thirdposition, and means for oper- Lating said second signal intermittentlyin relay, a second indicating relay, means for selectively energizingsaid relays, a signal, a control key, means for continuously operatingsaid signal in response to the energization of one of said relays andfor intermittently operating said signal in response to thedeenergization of said one of said relays when said control key is in apredetermined position, a second signal, means for continuouslyoperating said second signal in response to the energization of theother of said relays and for intermittently operating said second signalin response to the deenergization of said other relay when said controlkey is in a different predetermined position, and means forintermittently operating said first mentioned signal in response to thedeenergization of said one of said relays and said second signal inresponse sition.

CLYDE E. STEWART.

